L2TP over IPSEC not working


I’ve been using vyatta 6.6 and vyos 1.0.4 for simple things such as DHCP, NAT, Port forwarding, etc.
But now I need to configure a VPN. I’ve done that using PPTP and it was quite simple. No problems with NAT unlike when I follow the instructions to set up a L2TP over IPSec VPN.

In this scenario, I found that windows by default doesn’t allow clients behind NAT to connect, but by creating a registry key named “AssumeUDPEncapsulationContextOnSendRule” in HKLM\system\currentcontrolset\services\policyagent, it should work, but I was not able to connect either with windows or even a very old OS X 10.4. If I don’t use NAT, I can connect both in windows and OS X.

My setup

Vyos 1.0.4
Enable NAT-Traversal
interface eth0 (3 IP addresses)
interface eth1 (1 address; 2 vif for 2 VLANS - one of them the target of my intended VPN)

I’ve even disabled the firewall TO-Router just for testing purposes and it’s not the issue here. Anyway

Firewall To-Router open
UDP 1701
UDP 500
IPSec NAT-T UDP 4500
protocols ESP and GRE
I’ve also enable TCP besides UDP…just to be sure…
I’ve followed the instructions by a Vyatta official manual, still, I can’t get it to work.

Two questions:
Any idea of what the problem is? Should I use openvpn instead? If so, why?
Looking forward for some replies.

Managed to connect using OpenVPN. Curiously I had internet connection but I couldn’t ping the “Inside zone”. Isit necessary/possible to specify a route in vyos, or do I have to set one in each client?

push-route did the trick

Hello Dave,
1.0.4 is really old, retry 1.1.7 and if you still getting issue,
report it back to phabricator.vyos.net

Thanks for the reply. Well, I got it to work with openvpn.
Is it safe to install the newest version and overwrite the config.boot? I remembered that when I changed from vyatta 6.xx to vyos it was necessary to change some syntax.

from VyOS to VyOS should be just fine
from Vyatta before 6.5 sometimes you need to migrate manually(due syntax changes between 6.4 and 6.5)

Yes… Ithink it was 6.2!